---
title: "QuickStart API Assertions for Header Contains, Header Value, JSON Path Exists, JSON Validation"
slug: "quickstart-api-assertions-for-header-contains-header-value-json-path-exists-json-validation"
description: "Test Modeller has now expanded its capabilities to include a more extensive collection of API assertions straight out-of-the-box."
tags: ["API Testing", "QuickStart", "Test Modeller"]
updated: 2024-09-27T14:10:15Z
published: 2024-09-27T14:10:15Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://knowledge.curiositysoftware.ie/llms.txt
> Use this file to discover all available pages before exploring further.

# QuickStart API Assertions for Header Contains, Header Value, JSON Path Exists, JSON Validation

Quality Modeller has now expanded its capabilities to include a more extensive collection of API assertions straight out-of-the-box.

These new assertions enable the testing of API headers and JSON data returned from API requests, providing a more comprehensive set of tools for API testing.

[Embedded content](https://www.youtube.com/embed/u4PNcLNYTws?&wmode=opaque&rel=0)

To utilise the new **API Assertions,**open an existing **API Module collection** and edit the **API Function**you want to add the assertions to. ![](https://cdn.document360.io/77f722a6-2d0a-49fa-8074-572515a6c4b8/Images/Documentation/Screenshot%202023-09-18%20150432.png)

![](https://cdn.document360.io/77f722a6-2d0a-49fa-8074-572515a6c4b8/Images/Documentation/Screenshot%202023-09-18%20150413.png)

In the **Edit Function window**, open the**API Requests tab** and then the **Assertions SubTab.![](https://cdn.document360.io/77f722a6-2d0a-49fa-8074-572515a6c4b8/Images/Documentation/Screenshot%202023-09-18%20150420.png)**

In the **Assertions SubTab**, you can now add a range of assertions to run on your API Request execution, including Header Contains, Header Value, JSON Path Exists and more!

![](https://cdn.document360.io/77f722a6-2d0a-49fa-8074-572515a6c4b8/Images/Documentation/Screenshot%202023-09-18%20150325.png)

## Related

- [QuickStart API Automation](/quickstart-api-automation.md)